Master of Science, University of Toledo, 2020, Mechanical Engineering

Synthetic bone cements have been used as organic graft substitutes for since the early 20th century for multiple surgical procedures including orthopedic and dental applications. Ceramic bone cement can primarily consist of phosphate, magnesium, and calcium which are all completely biocompatible and have exceptional properties for bone growth. However, a few main issues with phosphate-based cements includes their poor mechanical and physical qualities such as compressive strength, crack propagation, injectability, and cell culturing. This limits the uses of the cement to non-load bearing bone filler. The other issue is the potential for phase separation during injection in surgery. This causes the liquid component of the cement to be filter pressed through the powder component, and making the cement not set and deteriorate before bone regeneration. However, this would be unacceptable for clinical use. Recent studies have shown that these properties can be better developed through the incorporation additives like fiber reinforcements and retarders, increasing the liquid to powder ratio (LPR), decreasing the particle size, and selecting an efficient syringe. These strategies were used to improve the injectability of the both calcium phosphate cement (CPC) and magnesium phosphate cement (MPC) while maintain the mechanical and biological properties. In the first study the CPC's LPR was increased to 0.4, their powder particle sizes were decreased to less than 90 μm, and a suitable amount of citric acid was added as a retarder. Also, in some of the composition of CPC newberyite (NB), a reinforcement platelet particle, was added in different amounts to test the strength of the cement. In the second study MPC's LPR was increased to 0.4, their powder particle sizes were decreased to less than 45 μm, and a suitable amount of boric acid was added as a retarder. All components of both the CPC and MPC have good biological properties and many papers have shown that changing these (open full item for complete abstract)

Committee: Sarit Bhaduri (Committee Chair); Matthew Franchetti (Committee Member); Vijay Goel (Committee Member) Subjects: Biomedical Engineering

Master of Science, The Ohio State University, 2009, Veterinary Clinical Sciences

Biomaterials can increase bone-implant interface stability. In this study four cortical screws were inserted in both 3rd metacarpal and 3rd metatarsal bones of 6 horses with calcium(Ca)-cement, magnesium(Mg)-cement, polymethylmethacrylate (PMMA) or left untreated. Specimens were harvested for analysis 5 or 182 days postoperatively. Radiography, biomechanical testing, histomorphometry and micro computed tomography were performed to characterize the bone-implant interfaces. Mg-cement significantly increased the extraction torque compared to control and Ca-cement and interface toughness compared to control, Ca-cement and PMMA. This improved interface strength was also observed during the 6 month follow-up period as one of the untreated screws and one Ca-treated screw backed out. Histologically there was 44% reduction in the quantity of Ca-cement and 69% reduction in the quantity of Mg-cement at 182 days. These results suggest that Mg-cement is a biodegradable bone cement, which can improve the biomechanical strength of the bone-implant interface.

Committee: Alicia Bertone PhD (Advisor); Steven Weisbrode PhD (Committee Member); Yvonne Elce DVM (Committee Member) Subjects: Surgery; Veterinary Services

Master of Science in Engineering, University of Akron, 2005, Biomedical Engineering

Antibiotic-impregnated polymethylmethacrylate (PMMA) bone cement has been used successfully to treat infected joint arthroplasties, and some surgeons advocate using antibiotic-impregnated PMMA bone cement prophylactically for all joint replacement surgeries. There is, however, concern that the added antibiotic reduces the mechanical properties of the cement. The general consensus is that the quasi-static mechanical properties of PMMA bone cement are reduced by the addition of antibiotic, but there is reason to believe that the fracture toughness of PMMA bone cement may increase with the addition of antibiotic. The objective of this study is to demonstrate the possible toughening effect of the addition of antibiotic to PMMA bone cement. The Mode I critical stress intensity factor or fracture toughness of Simplex® P bone cement with and without the addition of the antibiotic Tobramycin was determined experimentally using the procedures of ASTM Standard D5045. Cast rectangular compact tensile specimens were cyclically loaded to grow an initial fatigue crack to the recommended length. The specimen was then ramp-loaded to failure while the crack opening displacement was monitored. From the load-crack opening displacement data, the measured geometry of the test specimen and the fatigue crack, the Mode I fracture toughness was calculated. The fracture surfaces of representative specimens were examined by scanning electron microscopy to identify toughening mechanisms. The fracture toughness of Simplex® P (1.22 +/- 0.22 MPa√m, n = 9) bone cement was statistically significantly increased (p<0.05) by the manual addition of Tobramycin (1.45 +/- 0.08 MPa√m, n = 9) as it would be done at the time of surgery. The increase in fracture toughness of Simplex® P bone cement due to the addition of Tobramycin by the cement manufacturer (1.27 +/- 0.12 MPa√m, n = 9) did not reach statistical significance. Fracture surfaces of Simplex® P bone cement with added antibiotic were more convolute (open full item for complete abstract)

Committee: Michael Askew (Advisor) Subjects:

Master of Science in Engineering, University of Akron, 2006, Biomedical Engineering

Autogenous bone graft (ABG) is considered the evaluation standard for cranial defect reconstruction material. A variety of bone substitutes have been used as alternative materials for this procedure, each having its own advantages and disadvantages. Carbonated calcium phosphate (CCPP), a biomaterial form of hydroxyapatite (HA), has been increasingly used for cranial reconstructions. For defects of certain size and shape, CCPP is used with a titanium mesh for structural stability. At the present time there have been no published studies in the literature comparing the biomechanical and histological properties of these cranial bone reconstruction structures over time. In this study two different reconstruction structures were compared to autogenous bone grafts with respect to time. Reconstruction structure A (RCA) used a slow setting CCPP, whereas reconstruction structure B (RCB) used a fast setting CCPP. Unilateral or bilateral cranial defect reconstructions were conducted on sheep with full thickness defect sizes of 1.5 × 3.0 cm. A total of 24 sheep were divided into eight groups with post surgical periods of 0, 6 and 12 months. The skulls' biomechanical properties were evaluated using a free weight drop test protocol. In addition, intact parietal bone was also evaluated at 12 months as a control. Peak acceleration, peak force transmission and time to peak acceleration parameters obtained from the drop weight test were used for analysis. Immediately post-surgery there were no significant differences in any biomechanical characteristics of the experimental groups. At 12 months, the autogenous bone graft (ABG) reconstructions had a significantly superior impact characteristic compared to reconstructions of slow setting CCPP with titanium mesh scaffold and reconstructions of fast setting CCPP with titanium mesh scaffold (p<0.05). At 12 months ABG was not significantly different from the intact bone (p>0.05).

Committee: Glen Njus (Advisor) Subjects:

Master of Science, The Ohio State University, 1961, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1970, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1971, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1960, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 2023, Civil Engineering

The objective of this study is to analyze the effects of using agricultural biomass ash as a sustainable supplementary cementitious material. The potential for these waste materials to be used effectively in cementitious systems would promote global sustainability in both agriculture and construction. Three agricultural materials are explored in this study: hemp hurd, corn stover, and wheat straw. Corn stover and wheat straw have historically strong markets in the Midwest, and can generate significant waste. Hemp farming is a newer and strictly regulated enterprise in the United States, but the market has potential for growth due to the material's versatility. The chemical variability of each of these materials are contrasted among three sources mostly across the Midwest United States. The results can be assessed to inform future building code recommendations for alternative supplementary cementitious materials. The practicality of using these materials in cementitious systems is explored in this study by assessing the reactivity and performance of agricultural ashes at 10% and 20% replacement of ash for cement volume. The results of this study indicate that wheat straw ash and corn stover ash make naturally good pozzolans, assessed by their reactivity and contribution to improved long term hardened properties. These materials are viable for up to 20% volumetric replacement of cement for durability improvements, and up to 10% volumetric replacement for benefits to compressive strength. Hemp hurd ash showed lower reactivity in its natural state and did not perform like a traditional SCM. However, many chemical treatment techniques can be applied to optimize the properties of these materials by removing impurities, standardizing ash chemistry, and thereby improving the ash performance in cementitious systems. Additionally, variability in material chemistry and performance is significant in some results including reactivity.

Committee: Lisa Burris (Advisor); Anthony Massari (Committee Member); Halil Sezen (Committee Member) Subjects: Civil Engineering; Sustainability

Master of Science (MS), Bowling Green State University, 2023, Geology

The calcination process used to produce Portland Cement is one of the leading sources of global carbon dioxide (CO2) production. By reducing the amount of Portland cement used in concretes by adding in fillers, CO2 production in the concrete industry could be significantly reduced while still creating high-performing concrete. Various fillers have been tested, including crushed glass, limestone, recycled crushed concrete, and other industrial byproducts. However, even though switching from Portland Cement to blended cement (containing upwards of 15% filler) could provide companies with lower upfront costs and reduced carbon emissions while using industrial/aggregate byproducts, concrete production has changed very little. Due to the abundance of dolomite in Ohio mined for aggregate, it is a valuable resource that could be used and sold as filler. This study focuses on dolomites from the Lockport/Greenfield and Salina Group/Tymochtee formations and how these different dolomites function as fillers for concrete/mortar. The dolomite fillers were compared based on fluid and solid characteristics and were also compared to the more commonly used limestone filler from the Delaware/Columbus limestone formations. Filler replacement percentages of 10%, 20%, 30%, and 40% were added to cement and tested at different gradings based on the National Lime and Stone scale (DMI, 30's, 40's, and 80's). The mortar mixtures were brought to the low water-to-cement ratio (w/cm) of 0.35 and tested alongside an ASTM (American Society for Testing and Materials) control batch at a 0.485 w/cm ratio. The cement mixtures were tested using standard ASTM methods for slump flow and compressive strength. In addition, thin sections were analyzed to measure porosity, and polished sections were analyzed to measure paste volume between grains. The results show that using DMI-sized dolomite fillers, especially from the Salina Group dolomite, at 10-20% and a w/cm ratio of 0.35 exceeded the compressive str (open full item for complete abstract)

Committee: John Farver Ph.D. (Committee Chair); Ganming Liu Ph.D. (Committee Member); Yuning Fu Ph.D. (Committee Member) Subjects: Geology

Master of Arts (MA), Bowling Green State University, 1952, Biological Sciences

Committee: Thelma D'Almaine (Advisor) Subjects: Biology

Doctor of Philosophy, The Ohio State University, 2022, Civil Engineering

Traditional ordinary portland cement (OPC) concrete is one of the most used materials in the world, but sustainability concerns and the need for stronger and more durable systems have resulted in a search for novel cementitious systems. This work investigates two novel cementitious systems, calcium sulfoaluminate (CSA) cement, and bacterial concrete, understanding and improving their hydration kinetics, and evaluating effects on microstructural development and hardened binder properties with the goal of optimizing their use and moving these systems from lab to industrial scale. In order to enable longer working time for rapidly hardening CSA cement, CSA cement work explores (i) effects of retarding admixtures including citric acid, tartaric acid, borax, and EDTA on hydration, compressive strength, setting time, and phase development of CSA cement systems and (ii) working mechanisms of the retarders. The experimental results indicated that citric and tartaric acids yielded similar hydration and setting time trends, while borax retarded hydration reactions more efficiently for a given retarder dosage. However, retardation in both the carboxylic acids and borax is due to reductions in pH, resulting in changes in dissolution rates, and the formation of salt compounds. All retarders showed that increasing retarder dosage led to a decrease in compressive strength due to the slower ettringite development. Suitable curing methods for CSA cement samples were investigated and results displayed that wet curing beyond 3 days is not required for CSA cement mixes. The aim of the second system, the bacterial concrete, is to optimize the use of microorganisms in concrete and evaluate the practicability and the effect of integrating bacteria into concrete mixtures on strength, durability, and the service life with respect to reducing hairline cracks in the concrete microstructures. These objectives are addressed by investigating pure bacteria cultures, as well as developing bacterial sy (open full item for complete abstract)

Committee: Lisa Burris (Advisor); Zeynep Basaran Bundur (Committee Member); Natalie Hull (Committee Member); Anthony Massari (Committee Member) Subjects: Civil Engineering

Doctor of Philosophy, The Ohio State University, 2021, Civil Engineering

The high demand for concrete and the large amount of landfilled plastics necessitate an action to minimize their impacts on the environment. This study aims to recycle discarded plastics as a construction material to partially substitute the main ingredients of concrete (cement and aggregates). The objective is to make sure the strength and durability properties of concrete are not compromised while mitigating the sustainability concern. Discarded plastics including Polyethylene Terephthalate (PET), High-Density Polyethylene (HDPE), Polyvinyl Chloride (PVC), Low-Density Polyethylene (LDPE), Polypropylene (PP), and Polystyrene (PS) were reprocessed and incorporated in cement paste, mortar, and concrete. This study investigated changes in cement hydration kinetics and strength and durability of mortar and concrete due to partial replacement (5-15%) of their conventional ingredients with recycled plastics. The last part of this study included a life cycle assessment to evaluate changes in the greenhouse gas emissions that can result due to encapsulating discarded plastics in concrete. Research results indicated that plastic powders with a maximum particle size of 75 µm were not fully inert concerning early age hydration reactions. The effects of replacing natural fine aggregate with plastic particles on the properties of fresh and hardened mortar and concrete differed based on the plastic type and replacement ratio. Mortars incorporating plastics showed flowability, density, and compressive and flexural strengths lower than the control mortar. PS mortars showed the lowest compressive strength reduction (3-11%) compared to the control mortar. Most concrete samples incorporating 10% of plastics as a replacement for sand showed an average compressive strength reduction of 4%. The modulus of elasticity of plastic-modified concrete was 2 to 7% lower than the control concrete. The majority of plastic-aggregate concrete exhibited slight increases in tensile strength and Poi (open full item for complete abstract)

Committee: Halil Sezen Prof. (Advisor); Jose Castro Prof. (Committee Member); Lisa Burris Prof. (Committee Member) Subjects: Civil Engineering

Doctor of Philosophy, Case Western Reserve University, 2020, Biomedical Engineering

Periprosthetic joint infection (PJI) is one of the two leading causes of failure in arthroplasties and can develop inside of the bone as well as surrounding soft tissue. PJIs can be challenging to treat as initial diagnosis can be delayed and treatment typically involves administration of systemic antibiotics followed by removal of infected device. Traditionally, antibiotics have been directly mixed into poly(methyl methacrylate) (PMMA) bone cement to locally treat infections. However, this strategy often results in insufficient elution of drug for treatment of chronic infections and a limited range of antibiotics are compatible due to heat generated during polymerization. To overcome these shortcomings with antibiotic-PMMA, this work focused on development of PMMA composite material containing differing amounts of polymerized cyclodextrin (CD) microparticles. It was hypothesized that addition of CD microparticles to PMMA would enable post-implantation antibiotic refilling to occur and broaden the range of antibiotics compatible with PMMA to more effectively treat chronic PJIs without the need to remove the implant or expose patients to systemic antibiotics. This work first explores the emerging polymer technologies used to treat PJIs and then investigates a range of properties of PMMA containing CD microparticles and either a single or combination of antibiotics to treat broad-spectrum infections. Specifically, the porosity, compressive strength, antibiotic filling/refilling, antibiotic release, and antimicrobial properties were evaluated. Impact on functionality of CD and PMMA-CD composites in the presence of bacterial biofilm was explored. Furthermore, ex vivo models were developed to simulate how antibiotic refilling would reasonably occur in either soft or hard tissue. PMMA-CD composites were able to demonstrate refilling capacity with several antibiotics, resulting in lasting antimicrobial activity (> 60 days) to treat chronic, broad-spectrum PJIs. Composites (open full item for complete abstract)

Committee: Horst von Recum (Advisor); Steven Eppell (Committee Chair); Agata Exner (Committee Member); Eben Alsberg (Committee Member); Jonathan Pokorski (Committee Member) Subjects: Biomedical Engineering

Master of Science, The Ohio State University, 2019, Civil Engineering

The objective of this study was to examine the influence of the bulk chemical composition of fly ash on the compressive strength of concrete. Results from the compressive strength tests of 181 concrete samples that used partial cement replacement with fly ash were used as data to create multiple linear regression models. These models were compared to a baseline model to predict the compressive strength of concrete based on bulk composition of the fly ash. Both statistical and experimental methods were used for verification. This study found that the new Selected model measuring w/c ratio, w/c ratio, LOI, and the bulk percentage of six metal oxides, was better able to predict concrete 28-day strength. It finds that the current ASTM limits for fly ash are insufficient to fully explain the strength of concrete utilizing fly ash and that a better set of measurements is needed to determine if a fly ash is acceptable for use in concrete for structural applications.

Committee: Lisa Burris (Advisor); Tarunjit Butalia (Committee Member); Abdollah Shafieezadeh (Committee Member) Subjects: Civil Engineering

Master of Science (MS), Ohio University, 2019, Civil Engineering (Engineering and Technology)

This thesis evaluates natural and chemically stabilized subgrade soils from five project sites throughout Ohio. Three of the five project sites were historically known to have moderate to high sulfate concentrations in the natural soils (DEF-24-2.67-W, LAK- 2-7.76-W, MRW-71-3.17-N), while the other two sites were known to have little to no sulfate levels (CLA-70-13.98-W, CLI-73-6.52-E), and were used as controls. The main objective of the study was to compare in-situ and laboratory test results to determine if there were formations of ettringite or thaumasite in the soil, which can lead to sulfate heave and premature failure of pavement. Several field tests were performed such as PSPA, FWD, LWD, DCP, and SPT. Standard soil tests were performed on natural and chemically stabilized samples, such as gran size analysis, Atterberg limits, organic content, moisture content, and pH, as well as a chemical analysis comprising of neutralization potential, sulfate concentration, and X-ray diffraction (XRD). Analysis showed no major differences of moduli for pavement or soil layers between control and non-control. Results showed that sites where sulfates were known to exist, the chemically stabilized layers had sulfate concentrations greater than 3000 ppm and the pH was just barely greater than 10, which is an indication of concern for ettringite and thaumasite formation. However, the chemical analysis did not indicate formation of either mineral, therefore all conditions were not met.

Committee: Issam Khoury (Advisor) Subjects: Civil Engineering; Geotechnology; Soil Sciences

Master of Science, University of Toledo, 2018, Bioengineering

Long bone fractures are a commonly occurring injury that often require surgery in order to repair the fracture site completely. Despite concerned efforts to avoid bacterial contamination during surgery, surgical site infections (SSI) continue to be a major clinical complication. The development of antibacterial biomaterials that are capable of preventing bacterial attachment while aiding in bone growth and repair could prove to be beneficial to the field. Bioactive glass is a known biomaterial that is capable of producing hydroxyapatite (HA), a naturally occurring material with a chemical structure closely resembling that of human bone. In addition to osteoconductive benefits, bioactive glasses can be formulated to provide specific therapeutic benefits. In this study, a bioactive glass series was synthesized in which silver (Ag), a known antibacterial agent, was incorporated. After grinding the glass to an optimal particle size (<45m), the powders were used for further testing. In order to analyze the structure of the glass series, several characterization techniques were used to confirm that the bioactive glass had optimal structure, ion release, and HA production capabilities. Following characterization, cement discs were formulated and tested for antibacterial efficacy. The ZOI's (zones of inhibition) for SC2 cements were the largest when cultured with E. coli. A slight decrease in inhibition occurred when cultured with S. aureus. Cytocompatibility tests confirmed that the cement discs were not cytotoxic to M3CT3 mouse pre-osteoblastic cells. Overall, both SC1 (1% Ag composition) and SC2 (2% Ag composition) have optimal bioactive glass characteristics and reactivity while exhibiting antibacterial properties.

Committee: Aisling Coughlan (Committee Chair); Sarit Bhaduri (Committee Member); Kelly Marbaugh (Committee Member); Patricia Relue (Committee Member) Subjects: Biomedical Engineering; Biomedical Research; Engineering; Materials Science

Master of Science, University of Toledo, 2018, Mechanical Engineering

For several decades the calcium phosphate (CaP) cement compositions have been used as graft substitutes for orthopedic, spinal and dental implants. Besides their resemblance with the hard tissue (i.e. bone and teeth) minerals, the properties of good biocompatibility, bioactivity also have made them perfect candidate for orthopedic applications. However, their main drawbacks such as low mechanical properties like compressive strength, flexural strength and fracture toughness have limited their applications in only non-load bearing bone void fillers. Many recent studies have shown that these mechanical properties can be improved by incorporation of fibers or particles as reinforcement. Keeping this in mind, two different strategies were applied herein to enhance the mechanical performance of the calcium phosphate cement (CPC). In the first study, a magnesium phosphate compound named newberyite (MgHPO4.3H2O, NB) used to reinforce a CPC matrix. This inclusion makes these compositions system combined calcium phosphate-magnesium phosphate (CPC-MPC). In biological orthopedic applications there has been hardly any reports found in the literatures of combined CPC-MPC system. Not only this has improved the mechanical properties but also the introduction of Mg+ into CPC can improve the biological properties of the CPC cements. In the second study, a composite reinforcement termed as biphasic which consists of hydroxyapatite (HA) nano-whiskers and ß-Tricalcium Phosphate (ß-TCP) nanoparticles was reinforced to the same CPC matrix. Many papers have shown that reinforcing nano-fibers into a ceramic composite like CPC can significantly enhance the mechanical properties. Also, in this second study a different retarder than the first study was used for an attempt to reduce the porosities within the matrix that is generated during setting of the cement paste. This modification has shown to significantly improve the strength than the other retarder used in the in the first study of new (open full item for complete abstract)

Committee: Sarit B. Bhaduri (Committee Chair); Matthew J. Franchetti (Committee Member); Sorin Cioc (Committee Member) Subjects: Materials Science; Mechanical Engineering

Master of Science, University of Toledo, 2018, Mechanical Engineering

Calcium phosphate (CaP) compounds have been used as orthopedic, spinal and dental implants, and bone graft substitutes for several decades. Their good biocompatibility and bioactivity and most importantly their resemblance to bone and teeth mineral, make them perfect for orthopedic applications. However, the available CaPs possess a major drawback of slow bone formation rate resulting in a longer time for recovery of patients. Thus, this affects the psychological, physical and economic well-being of the patient and their family members. Electrical stimulation has been proven to enhance the osseous formation in different animal studies which in turn led towards the development of different piezoelectric devices and piezoelectric/biomaterial composites. Keeping these facts in mind, present work utilized the piezoelectric nature of Barium titanate (BT) into the different CaP compounds. The prime focus of this thesis is to enhance the electrical properties of CaP such that it helps to promote early osteogenesis. Furthermore, the minimally invasive surgery demands for the injectable self-setting CaP formulations whereas dense CaP scaffolds are most for the load-bearing applications. To address these applications, we carried out two different projects, first being injectable monetite based piezoelectric bone cement and second sintered HA-BT piezobiocomposites. Interestingly, as far as our knowledge, no literature is available on the CaP bone cement with piezoelectric properties. Thus, the development of piezo- CaP bone cement is the first of its kind and signifies the novelty of this thesis. Here, BT particles act as a source of electrical energy during normal physical loading conditions. The incorporation of BT into CaPs results in three major advantages. First, it improves the electrical properties (dielectric constant, piezoelectric coefficient) of the CaPs. Second, considering CaPs as a preferable cell-growing scaffold, BT incorporation enhances osteoblast cell activ (open full item for complete abstract)

Committee: Sarit B. Bhaduri Ph.D. (Committee Chair); Mehdi Pourazady Ph.D. (Committee Member); Matthew Franchetti Ph.D. (Committee Member) Subjects: Mechanical Engineering

Doctor of Philosophy, University of Akron, 2017, Polymer Engineering

Poly(ethylene glycol)s (PEGs) are an important class of polymeric materials. In addition to standard linear PEGs, polymers synthesized from (meth)acrylated PEGs are specially versatile in modern technological applications. Comb-like copolymers derived from (meth)acrylated PEGs, such as polycarboxylate ethers (PCEs) are widely used as hydration and setting modifiers in cement while the working mechanisms in cement hydration have remained uncertain. The first part of this dissertation uncovers correlations between copolymer architecture and setting properties of cement for a range of synthesized PCEs architecture. Adsorption of PCEs on calcium silicate hydrate surfaces involves migration of Ca2+ ions in the acrylate backbone to the calcium silicate hydrate surface and subsequent ion pairing of the anionic polymer backbone with the positively charged surfaces of calcium-silicate-hydrate (C-S-H) gel. Two consistent sets of property correlations are identified as a function of copolymer design. The adsorption strength of PCEs onto cement pastes, the conductivity, and retardation of cement hydration correlate in the same order. The water-to-cement ratio necessary for processing, zeta potentials, and the fluidity of the cement pastes correlate in a different order. The adsorption set directly correlates with the density of carboxylate groups, leading to strong, flexible ionic packing of multimolecular layers for low density and short length of side chains. The fluidity increases with density and length of PEG side chains, leading to less flexible, flat-on conformation, and lower adsorbed mass. Best dispersion of cement particles and greatest water reduction require a compromise reached by low density and intermediate length of PEG side chains. The mechanisms support the design of cement materials and related particle dispersions. A new series of ultraviolet (UV) curable electrical contact stabilization materials, which contain polypropylene glycol (PPG)-block-polyeth (open full item for complete abstract)

Committee: Mark Soucek (Advisor); Sadhan Jana (Committee Chair); Miko Cakmak (Committee Member); Toshikazu Miyoshi (Committee Member); Richard Elliott (Committee Member) Subjects: Polymer Chemistry; Polymers